With respect to the Custom Function reassign options on the 5D Mark III, I saw one that Neuro suggested and that was to reassign the DOF button to One Shot > AI Servo and visa versa. After setting this up and pressing the "Q" button I noted all the settings including One Shot as displayed on the screen. However pressing the DOF button did not alter the One Shot mode on the back menu via the Q button. In calling Canon this is apparently is now a bug as you can only see this toggle occur on the Top of the camera or by pressing the INFO button 3x. I guess its not safe to say 2 out 3 ain't bad. The tech took the report I had offered and listed it as a flaw and hope we see this update in the firmware forthcoming.

Onto the GP-E2 (GPS) - I've noted this phenomena several times where the time stamp on the camera has been altered by an hour when the GPS is connected. Of course one has to supercede the other..either the camera time or the GPS clock. Basically with the correct time zone and DLS "on" the clock goes off by an hour. I ultimately opted to go into the GPS settings and turn off Daylight Savings time and this seemed to cure the issue. The tech was able to repeat this same issue and advised I turn daylight savings back on in the spring. Not so. That defeats the whole purpose of DLS to begin with. This is clearly a bug. He ultimately agreed when I presented "my PC is on DLS I don't ever mess with that time why should I have to do this with your GPS device"? I hope in this next firmware release we will see resolutions to both of the above issues.

Good catch on the focus mode toggle display - I'll have to check that on my 1D X (when toggling, I'm always looking through the VF, so I've not checked either LCD).

I'm not sure the daylight savings issue is a bug. Wrong behavior, yes, but not an error in programming. When you state that you, "...opted to go into the GPS settings and turn off Daylight Savings time," that doesn't look like it's possible. The camera time setting is on the same tools menu as the GPS device option, but it appears from the manual there's not a way to specify daylight savings in the GPS setting, just the camera setting. The camera setting is doing what it's supposed to - taking the set time (whether set manually or automatically by GPS) and adding an hour, exactly as the manual says it does. That's what I mean by 'not a bug'.

Some devices have the start/end dates for daylight savings programmed in (and sometimes, like the DVD player/recorder in one of our rooms, that's bad - it was made before Congress changed the dates, so it now 'falls back' a few weeks early and 'springs forward' a few weeks late).

Try leaving the daylight savings camera time setting off, and see what happens when DST starts in two months.

Good catch on the focus mode toggle display - I'll have to check that on my 1D X (when toggling, I'm always looking through the VF, so I've not checked either LCD).

I'm not sure the daylight savings issue is a bug. Wrong behavior, yes, but not an error in programming. When you state that you, "...opted to go into the GPS settings and turn off Daylight Savings time," that doesn't look like it's possible. ..........Try leaving the daylight savings camera time setting off, and see what happens when DST starts in two months.

There is a setting for this (don't have it connected now but as I recall it has a sun icon). you can toggle this on and off - it's within the city name..here it says Los Angeles. I have not had an issue since I've toggled this off. The time stamps are all correct now so I'm fairly confident that was the issue. You raise an interesting point and that is to turn off DLS on the camera. That certainly is another work around though since I rely on the camera time more than the GPS (not always connected) I may stay put and wait to hear back on what canon has to say. PS did you get the latest version of the 600mm @ F/4 ?

I'm not sure if there's a bug. My 5DIII toggles properly on either of the LCDs and the viewfinder. If the default is AI servo it toggles to One shot, and vice versa. If the Q menu is activated, nothing happens when the DOF button is pressed as expected. You have to make a selection first and get out of the Q menu. FYI, the toggle is only temporary while the DOF is pressed. But I'm sure you already knew that.

If the Q menu is activated, nothing happens when the DOF button is pressed as expected.

true however if you note the top of the camera it does change. I rarely if ever use the top of the camera for navigation / changes..more reliant on the larger 3" screen with the Q button. I thought it made no sense that the change occurs on top or if you press Info 3x but not on the Q menu. it should be all succinct on "any menu" point being.

There is a setting for this (don't have it connected now but as I recall it has a sun icon). you can toggle this on and off - it's within the city name..here it says Los Angeles. I have not had an issue since I've toggled this off. The time stamps are all correct now so I'm fairly confident that was the issue. You raise an interesting point and that is to turn off DLS on the camera. That certainly is another work around though since I rely on the camera time more than the GPS (not always connected) I may stay put and wait to hear back on what canon has to say. PS did you get the latest version of the 600mm @ F/4 ?

My point was that the sun icon by the city name is part of the camera time setting, not a GPS function. It's on the same menu screen as 'GPS functions' but a different line, meaning it's a camera function. Or with the GP-E2 connected, is there a second place to set city and 'sun' that comes up when you highlight GPS functions and press Set? (Why would the GPS setting need a city entered, isn't that the point of a GPS?!?). Assuming there's only one such setting, leaving the sun/DST off is the way to go, since we're currently on standard time.